Transformer



June 14 1927. 1,631 955 C- BERG MAN TRANSFORMER Filed April 12, 1924 2Sheets-Sheet 1 Hllllllli lllllll |||l Illll l I l J 5 v *4 A E 8 8 6 1111 i7 4 INVENTOR Carl/5 BYWJGAF- 1/45 ATTORNEY 1,9 June 14, 1927, c.BERGMAN I I 55 TRANSFORMER Filed April 12, 1924 2 Sheets-Sheet 2mun-TIM? BYZl/m Patented June 14, 1927.

UNITED 4 STATES CARL BERGMAN, OF IBERGENFIELD, NEW

TRANSFORMER.

Application filed April 12, 1924. Serial No. 706,016.

My invention relates to transformers, my particular purpose being toproduce a small, neat and compact transformer suitable for oflice use,and provided with means for con- 5 necting it with leads from streetmains, the device having a number of advantages and being adapted\forenergizing small appliances such as electric cauteries and miniatureelectric lamps as commonly used by surgeons and dentists.

Reference is made to the accompanying drawing forming a part of thisspecification and in which like reference characters indicate like partsthroughout the several l figures.

Figure 1 is a plan view of my improved transformer. I

Figure 2 is a cross section through the same, substantially upon theline 22 of Figure 1, looking in the direction indicated by the arrows.

Figure 3 is a fragmentary view, partly,

a plan and partly a section, showing various details of the transformer.

Figure 4 is a section on the line 4-4 of Figure 3, looking in the,direction indicated by the arrows. .Figure 5 is a plan view of a portionof the laminated core of the transformer. Figure 6 is a diagram of thewiring. Figure 7 is a fragmentary section showing for certain parts aform difl'ering slightly from the one appearing in Figures 1 to 5inclusive. I

A casing wall 8, havin' a general annular form, encloses most of te'parts 1 Detachably engaging the casing wall 8 is a. casing head 9-having generally the "form of a disk, and s the apparatus. The casinghead 9 is provided with a raised head 10 integral with it. Spacing posts11 are connected with the bead 10 and extend upwardly therefrom, andsupport various parts, as hereinafter more fully described. Screws 13,14, connectcd with the spacing posts hold these posts in position.

Another casing head is shown at 15, and engages the casing wall 8. Thespacing posts 11 are connectedjwith this casing head.

A laminated core 16, made up of stamp-.

ings of iron or steel and having a general annular form, serves as thetransformer core. This core carries three sup orting pins '17, made ofinsulating material and erving as a base for each insert endwise intothe core as indicated in Figures 4 and 5. These supportin pins, eachprovided with a hole 17 as in icated in Figure 5, are mounted upon thespacing posts 11 and thus supported by the casing head 15, so thatthecore 16 and parts carried thereby are insulated from this casing headand from other metallic parts.

A jacket 18 of insulating material encompasses the laminated core 16,and thoroughly insulates it throughout its entire extent, Wound upon-thejacket 18 is the primary winding 19. The primary winding extendsthroughout the entire length of the core 16, and is preferably made offine wire. This enables it to be safely connected with' street mains, orwith taps leading therefromor in other words, to be used with ordinarycommercial currents.

The ends of the primary winding 19 are shown in Figure 3 at 20, 21, andare secured to plug connections 22, 23, carried by a block 24 ofinsulating material. By aid of the plug connections, the rimary windingcan be instantly connected with or disconnected from any availablesource of alternating current. a

A jacket 25 of insulating material covers and also conceals the primarywinding 19. Coiled upon the jacket 25 of insulating material, andconsequently wound around the core 16 and primary winding 19, are twosecondary windings 26, 27, disposed upon. opposite sides of the core, asmay be understood from Figure 3.

. The secondary winding, 26 comprises a few turns of coarse wire, and isthus adapted to supply currents of low voltage, suitable for heating anelectric cautery. The winding 27 is made of wire somewhat finer than thesecondary winding 26, and comprises a greater number of turns, Thesecondary winding 27 is adapted. to supply currents suitable forenergizlng a miniature lamp.

For convenience I designate the secondary winding 26 as a heatingcoil,.and the secondary winding 27 as a lighting coil.

Four binding posts 28, 29, 3'1, 32, are carried by the casing head 15.The binding posts 29 and 32 are mounted directly upon this casing head,and in direct metallic com.- munication therewith. The binding post 28is insulated from the casing head and is connected with the adjacent endof the secondstrips of copper and thus having a laminated tent and inthe same direction.

structure. This contact spring presses upon the adjacent convolutions ofthe secondary winding 26, and is provided with a stubby downturned endportion 37, which makes at all times a sliding engagement with thecasing head. By this arrangement the contact spring 36 is always inmetallic communicat1on with the casing head 9, and is grounded if thecasing is grounded.

Mounted rigidly upon the shaft 34 is a stop arm 38, having the formindicated more particularly in Figure 1, and serving to some extent as apointer. Since the contact spring 36 and the knob 35 are each mountedrigidly upon the shaft 34, it follows that these parts move together andpractically as a unit, so that whenever the knob is turned by hand toany extent in either direction the contact spring and the stop arm 38must each be turned correspondingly, to the same ex- Closely associatedwith the stop arm 38, the casing head 9 is provided with a scale andwith numerals spaced apart and serving as graduations. This scale as awhole is indicated in Figure 1 by the numeral 39, and is used inconnection with the measurement and control of currents used for heatinga cautery, as hereinafter more fully described.

Mounted adjacent the scale 39 is a rib 40 having a general arcuate form,and detachably fitted upon it is a clamping block 41, carrying a setscrew 41. The operator by turning this set screw in one direction cantighten the clamping block 41 upon the rib 40, and by turning the setscrew in the opposite direction can loosen the clamping block. Thus theclamping block can be loosened and moved along the rib 40 in eitherdirection .and to any extent permitted b the length of this rib, andthen tightene A pair of stop pins 38, 38 are mounted upon the casinghead 15, and are disposed in proximity to the ends of the rib 40. Thestop arm 38 can travel from one of these stop pins to the other, exceptwhen the clamping block 41 occupies a position somewhere on the rib 40and intermediate the stop pins. In this event the stop arm 38 is free tomove from the stop pin 38 to clamping block 41. With the stop arm 38occupying the position indicated for it in Figure 4, it can moveanywhere between 0 and 4, and with the stop arm resting against theclamping block in the position here indicated, the cautery will receive4 amperes or other units of current.

Another stop arm 42, somewhat similar to the stop arm 38, is journaledupon the shaft 34, and may be moved relatively to the same by hand. Forthis purpose the stop arm 42 carries a thumb piece 43. The operator bygrasping the thumb piece 43 can move the stop arm 42 back and forth. Apair of stop pins 44 and 45 are mounted upon the casing head 15, anddefine the extremes of travel possible for the stop arm 42. Associatedwith this stop arm is a scale 46, provided in this instance withnumerals from 0 to 5,.and used for measuring and controllingcurrentsused in connection with an electric lamp, as hereinafter more fullydescribed. Mounted upon the casing head 15 and disposed adjacent thescale 46 is a rib 47 of arcuate form. The scale 46 and rib 47 are instructure and action very much like the scale 39 and rib 40 abovedescribed. A clamping block 48, PI'OVldGd'Wlth a set screw 49, isdetachably and .adjustably mounted upon the rib 47 and is used inconnection with the scale 46 in the manner I above described inreference to the clamping b10ck'4l, associated with the scale '39. Theoperator by shifting the clamping block 48 into different positionsalong the rib 47 can limit the travel'allowed for the stop arm 42, andin doing this can regulate the amount of current controlled by theposition of the stop arm 42. With theapparatus in the conditionindicated in Figure 1, the maximum current permitted by the position ofthe stop arm 42 is three amperes, or other units of measurementcontemplated by the numerals of the scale 46.

Instead ofthe ribs 40 and 47, provided with clamping blocks 41 and 48, Imay use as an equivalent the structure shown in Figure 7. Here thecasing head appears at 50 and carries a rib 51 provided with a channel52, and merging into this channel is a slot 53. A bolt 54 extendsthroughthe slot 53, and is provided with a head 55 which fits loosely withinthe channel. A washer 56 encircles the bolt, and rests upon the rib 51.

A set screw 57 engages the bolt, and is used I for tightening andloosening the same. The operator by turning the set screw 57 andloosening the bolt can'slide the bolt along the rib, and then by turningthe set screw in the opposite direction can tighten the bolt. The beltwith its washer 56 serves the same purpose as either of the clampingblocks 41. 48. A contact spring 58 is connected with the stop arm 42 bymeans of a hub 34" through which the shaft 34 extends. Thus the contactspring 58 turns. with the stop arm 42, and since the hub 34 is looserelatively to the shaft, the movement of the current flowing through thesecondary winding 27 may be varied.

I will now explain the diagram shown in Figure 6.

y means of the plug connections 22, 23, above described, the primarywinding 19 is connected directly with a pair of feed wires 59, and thussupplied with alternating current, and energized accordingly. A pair ofconductors and 61, such as conducting coils or wires, are connected withthe bind ing posts 31, 32, and lead therefrom to an incandescent lamp 62of the type used in surgery.

Similarly a pair of conductors 63 and 64, are connected with the bindingposts 28, 29, and lead therefrom to a cautery, indicateddiagrammatically at 65.

The lamp circuit is shown as grounded at 66, and the cautery circuit at67. These two grounds are very conveniently made by simply grounding thecasing, in any convenient manner.

In my device there 1s considerable economy of construction due to thearrangement just described. That is to say, there is a' saving due tothe fact that no effort whatever is made to insulate the shaft 34 or anyof the parts carried by it, since the shaft 34 and all of its variousmetallic connections may be considered as grounded through the casing.

The only insulation required, therefore, is for the various windings,and the very simple electrical connections absolutely necessary forconveying the currents into and out of these windings.

I do not limit myself to the particular mechanism shown, as variationsmay be made therein without departing from my invention, the scope ofwhich is commensurate with my claims.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is as follows:

1. A device of the character described comprising a casing provided witha pair of casing heads, a plurality of posts each extending through saidcasing and connected with both of said casing heads, a trans former corehaving a general annular form and provided with openings, members ofinsulating material disposed within said openings and extendingtherefrom, said members of insulating material being connected with saidposts for the purpose of supporting said coreby aid thereof, transformerwindings mounted upon said core and insulated therefrom, and mechanismmounted upon one of said casing heads and connected with saidtransformer windings for enabling the oper ator to control saidtransformer windings.

2. In a device of the character described the combination of a casing,astop arm journaled upon said casing and movable angularly in relationthereto, means controllable by the operator for adjusting the limits oftravel of said stop arm, a transformer mounted within said casing,movable contact mechanism connected with said transformer vfor thepurpose of controlling electric currents generated thereby, said movablecontact mechanism being connected with said stop arm and controllable bythe different positions intowhich said stop arm is moved, and means forenergizing said transformer.

3. In a device of the character described the combination of a casingprovided with a casing head, a rib mounted upon said casing head, aclamping block connected with said rib and adjustable bodily intodifierent positions along the same, a stop arm journaled upon saidcasing head and movable into different positions relatively to said rib,said clamping block serving as a stop for limiting the travel of saidstop arm, a transformer mounted within said casing, movable contactmechanism connected with said transformer for the purpose of controllingcurrents generated thereby, said movable contact mechanism beingconnected with said stop arm and controllable by the travel thereofrelatively to said clamping block, and means for energizing saidtransformer.

4. In a device of the character described the combination of a casingprovided with a casing head, a plurality of ribs carried by said casinghead, each of said ribs having an arcuate form, a pair of clampingblocks, one for each rib, each clamping block being connected with therib with which it is associated and adjustable bodily into differentpositions along the same, a plurality of stop arms journaled relativelyto said casing head and movable into different positions relatively tosaid ribs, a clamping block connected with each rib for limiting thetravel of one of said stop arms relatively thereto, a transformermounted within said casing, a plurality of movable contact mechanismsconnected with said transformer for the purpose of controlling currentsgenerated thereby, connections from said movable contact mechanisms tosaid stop arms for the purpose of enabling said movable contactmechanisms to be limited by movements of said stop arms, and means forenergizing said transformer.

5. In a device of the character described the combination of a casingprovided with a casing head, a stop arm journaled upon said casing headand movable angularly,

means controllable by the operator for ada transformer mounted Withinsaid casing,

movable contact mechanism connected With said transformer for thepurpose of controlling electric currents generated thereby, said movablecontact mechanism being connected With said stop arm and controllable bythe different positions into which said stop arm is moved, and means forenergizing said transformer.

6. In a device of the character described the combination of a casingprovided with a casing head, a pair of stop arms disposed adjacent saidcasing head and journaled to turn upon a common axial center, said stoparms being movable independently of each other, means controllable bythe operator for limiting to any desired extent the travel of 1 therespective stop arms, a transformer mounted Within said casing, a pairof movable contact mechanisms connected With said transformer forcontrolling different sets of electric currents generated thereby,connections vfrom said contact mechanisms to said stop arms for thepurpose of enabling each of the stop arms to actuate one of the contactmechanisms, and means for energizing said transformer.

Signed at New York, in the county of New York and State of New York,this 8th day of April, 1924.

CARL BERGMAN.

